From director Ruben Fleischer (Zombieland), the crime drama Gangster Squad is set in Los Angeles in 1949, when ruthless mob king Mickey Cohen (Sean Penn) made a business out of drugs, guns and prostitutes, all thanks to the police and politicians being on his payroll. He thought no one and nothing could stop him, until a small, secret crew of LAPD officers, led by Sgt. John O’Mara (Josh Brolin) and Sgt. Jerry Wooters (Ryan Gosling), came together to take back the city and tear Cohen’s world apart. The film also stars Emma Stone, Nick Nolte, Anthony Mackie, Giovanni Ribisi, Michael Peña, Robert Patrick and Mireille Enos. For more on the film, be sure to check out our set visit coverage here, and watch six clips.

During a press conference at the film’s press day, actors Josh Brolin, Ryan Gosling and Emma Stone, along with Fleischer, talked about finding the tone of the film, the most challenging scene to shoot, what they did to get into the time period, how they viewed their characters, assembling such a talented supporting cast, working with an actor as intense as Sean Penn, having a sensitivity about extreme violence in films, and the decision to reshoot one of the more intense scenes. Check out what they had to say after the jump.

Question: Ruben, how did you decide on the tone you wanted for this film?

RUBEN FLEISCHER: For me, coming from a comedy background and making the transition to a more action-filled, dramatic movie, I had a lot of learning to do, in the process. Luckily, the cast was filled with some of the most talented actors you can assemble, and I think that guided, to a large degree, the feeling of the movie, with the authenticity of their performances. And then, as a filmmaker, I had a real opportunity to stretch my legs with these bigger action sequences and tried to make it as exciting and as entertaining as possible.

Josh and Ryan, which was the most challenging scene for you to shoot?

RYAN GOSLING: It was challenging for me when I realized that I was not going to get a Tommy gun. I thought, for sure, that I would have one, but instead I got a little tiny lady gun. Josh had to hide the Tommy guns. That was difficult for me.

JOSH BROLIN: I think the fight with Sean [Penn] was the most difficult. Sean didn’t rehearse as much as I did, so his fists were flying wildly, during the fight, hoping they got something usable. It was a tough fight that we rehearsed for many, many, many weeks and I love the way that it turned out. But both of us, being the current and ex-smokers that we are, found it the most challenging, on an oxygen level.

Did any punches connect?

BROLIN: Possibly.

FLEISCHER: I’ve gotta give credit to Josh and Sean ‘cause that fight sequence is entirely them. There were no stunt doubles, and we shot over the course of three nights. The shooting of the fight sequences started at midnight, and we went until about 6 am. And they were doing that incredibly brutal, physical, wet fight, at all hours of the night.

Ryan and Emma, what do you enjoy about working with each other?

GOSLING: Well, Emma owes me money and the only way I can try to get that back is by doing movies with her. She still owes me that money. It was hard for us to be serious together. We had made this comedy together (Crazy, Stupid, Love), where we were a couple of knuckleheads. And then, we thought, “Oh, this would be fun to work on together again,” but we had to try to be serious. I tried to pretend that I was Humphrey Bogart, and that made it difficult.

EMMA STONE: I want to work with Ryan, a lot, if he’ll have me.

For the actors, did you do anything specific to help you get into this time period?

GOSLING: The wool was quite itchy and I had a rash, so I channeled that irritation into my hatred for the gangsters.

BROLIN: We got to talk to some people. We got to talk to John O’Mara’s daughter. You create a composite character and see how it works. And then, you get to the set and Ryan [Gosling] is doing something this way and Sean [Penn] is doing something that way, and you adjust and hopefully find the best dynamic that you can create. It was less of a laconic character when we filmed it, but through editing, we found it much better to have me shut up and go for more of that Bogey and Clint Eastwood type of thing. That seemed to balance things out better. Even what you do on the set isn’t necessarily right. Thank god for editing. But, this was more of a composite thing. You lend yourself to the romantic idea that you have of that time, and what that is for you, personally.

How did you approach your characters and how did you view them, as individuals?

BROLIN: I think he has a lot of integrity. I like the fact that it’s this old idea of somebody who has the honor of not following the manual of what they said law was, back then. Law was a lot less paranoid than it is now, and the boundaries of law were a lot more malleable then than they are now. Guys thought outside the box. The good guy was not necessarily the good guy. He had to think dirty, in order to snuff out these guys who were trying to turn Los Angeles into the Wild West and into a cesspool. After he got back from WWII, I think he was shocked about how much Los Angeles had changed. And instead of being narcissistic and selfish, he thought about the future of his kids and all of the stuff that we think about now. Whether we’re truly that kind of country or not, we were, much more so, back then. I asked my pop about what it was like back then, and he didn’t tell me anything. I’m seventh generation Californian. And then, he finally got to the set one day, and we were looking out at this street that had been recreated because of the cars, and he just went off on these stories about how, when he was nine years old, he used to peak in the back door of Slapsie Maxie’s and go down the street looking for Mickey Cohen and his goons. He was talking about all of this corruption and the idea of gangsters as celebrities back then, and yet there was an innocence in everything he was saying. That’s the difference. You can manifest something honorable and have it have an impact.

STONE: My character wasn’t based on a real person, which was a nice jumping off point, pressure wise. What we had talked about was the fact that she had come out to Los Angeles to be famous, and she ended up on the arm of someone who was really notorious, which is what reality show people are sometimes like today. She was just famous by association or by proxy. I thought that was interesting. Something pretty heartbreaking was going on, underneath the surface. I didn’t get a lot of time with the guys, so each scene was just about trying to focus on bringing as much of that to the surface as I possibly could.

GOSLING: I’ve always admired how Bugs Bunny was not above dressing like a lady to get out of trouble. I thought that could be interesting for this, in some way. He’s this person trying to avoid and make himself inconspicuous. That was in my head. But, I was also trying to relate that to the idea that this was a real person. I think it’s important to know that the man himself was much braver and a more admirable character than the version of him that I play in the film. But, for dramatic purposes, it was necessary to have the character have a conflict and be effected personally by the death of this shoe-shine kid,and then be provoked into joining the squad. It was about trying to balance what felt best for the film, but also trying to honor the man himself. I did find it difficult.

Ryan, did you find a lot of material on Sgt. Jerry Wooters?

GOSLING: Yeah, and I also got a chance to meet some family members. His kids came to the set and told me a lot of great stories and details. Apparently, when he ashed his cigarette, he would ash in the cuff of his pants. And then, at the end of the day, he would dump all of the ashes out of his cuffs.

How did you assemble such a talented supporting cast?

BROLIN: You start these things out and you have this studio-propelled, value dream team, and you’re trying to get who’s of most value, it’s great when that doesn’t necessarily work. You go down this idea of rugs on the ladder, and they turn out to be the best actors you could possibly get for those parts. I think we came out with an amazing cast that wouldn’t necessarily do smaller parts like this ‘cause a lot of those guys are lead guys now. It was great ‘cause I’m usually the guy who’s fucking around all the time, on the set. With this one, I got to stand back. When you have Anthony Mackie, Michael Peña and Robert Patrick on a set together, it’s absolute fucking chaos. It’s a lot of fun to be able to watch that. So, they created a vortex that became what you see on film, which I think is the great exhale of this film. Within all this testosterone, it’s because of them that you get to take a breath. And then, the impact of all the other stuff is much more apparent because of that.

FLEISCHER: I feel really lucky to have gotten to work with so many talented people, especially as a young director. I learned so much from all of them. For each role, there couldn’t have been a better person to fill it. Everyone was pitch perfect and really brought so much to it. The squad did function as a squad, both off and on screen. There was a lot of camaraderie among the actors, and also a lot of chaos. I felt like a school teacher sometimes, trying to control the class. It was a little bit hectic.

Ruben, was it intentional to have American actors in the roles of the L.A. cops?

FLEISCHER: Yeah. Well, Ryan [Gosling] is Canadian, but it was honestly really important to me that we have North American actors not doing accents. Josh [Brolin] is seventh generation Californian. Los Angeles is a big character in the film, and I love that he is representative of L.A., just because he is so California. Sean Penn is also a native Angeleno. His grandparents own a bakery in Boyle Heights, where Mickey Cohen was from, and he used to do bread runs for their bakery in his high school summers. There is a very serious personal connection for a lot of the actors in the film, and I was proud of the fact that it is a largely North American cast. Jack Whalen, who’s played by Sullivan Stapleton, was our only foreign actor in the film.

What was it like to work with as intense an actor as Sean Penn?

FLEISCHER: I was really nervous to work with him, honestly, not only ‘cause he’s one of the greatest living actors, but also because he’s a great director. I can promise you that I didn’t get a lot of sleep, the night before my first day of shooting with him. But, I couldn’t have asked for a more collaborative or generous partner in the film. When he jumps in, he jumps in with both feet. He brought so many ideas to the character, as well as to the film. He was incredibly collaborative and generous with his talent.

BROLIN: Sean is great. We’ve known each other for a long time, and I don’t find him very intense, myself. He’s an amazing actor. We have a lot of fun. We work similarly, and we have a lot of fun on the set. We don’t go around with furrowed brows. We have a place to springboard from and dive into, so working with him is a great pleasure. When you’re looking at somebody in the pupil, and they’re doing their best to be as intense as they can and you’re doing the same, and you know each other as well as we do, it’s kind of dumb. But, hopefully audiences will enjoy it.

STONE: My character essentially is the forgotten girl on his arm, a lot of the time, so I said about one line to him. For the most part, he’s doing his business while I’m off to the side. So, I was watching him more than anything. However you feel, as an audience, is how I felt, as an actor.

BROLIN: The great thing about him is that you look at him and go, “That’s the guy who was Harvey Milk.” That’s the shocking thing about Sean. His conviction is so complete when he’s doing something, but then you remember, as a fan, “Holy shit, this is the same guy who did this. This is the guy who has the ability to be as vulnerable as he is intense.” That’s what makes him so special, at least to me.

FLEISCHER: He’s not just vulnerable and intense, but he has a real sense of humor. Before the movie started, we all went to see Fast Times at Ridgemont High and the Hollywood Forever Cemetery. And that’s who Mickey was. He was scary and intense, but he also had a real sense of humor. He was funny and quirky.

Josh, what was it like to shoot that big fight scene at the Plaza Hotel?

BROLIN: You need to watch the gag reel, and then you’ll understand. Those things are so serious, and you have to make decisions. It’s all so super cool, but the reality is that you’re just an actor, living this childlike existence. It’s fun, but at the same time, it’s very serious. And we’ve had a lot of things come up lately that make it very serious. The impact that that has, you have to understand that, when you’re doing something like that, you’re lending to the story that you’ve already decided to do. It’s not about, “How do we treat this in a way that might be more respectful than not?” You’ve already decided to do that type of film. It was a lot of fun doing it, but for a guy who doesn’t have any guns myself, I was a little nervous. And I live in a very Republican area in Central Coast, California where I’m surrounded by gun-toting guys. I like tactile things. I miss a good fight. If you see the gag reel, you’ll see how lost we were.

Is there a special sensitivity about this kind of extreme violence, because of recent events?

BROLIN: Of course, there’s a sensitivity. But, you have to look at the grand scheme of things from a universal standpoint. You have video games. You have psycho-pharmaceuticals. You have the lowest employment. You have parents who aren’t home. You have CNN, who gloms onto the worst of what’s going on, and not necessarily the best or the most heroic. There are many different factors. There’s no one reason. There’s always been violence in movies, and there will always be violence in movies. Whether it lends to the one psychotic that’s out there, thinking the worst thoughts you could possibly thing, is always going to be a mystery.

What do you think this movie has to say about what our society is willing to accept or not accept?

FLEISCHER: I think this movie is about standing up for their beliefs and doing what’s right. It’s a celebration of these cops who rid L.A. of organized crime, of vice and of corruption. We haven’t had organized crime since they got rid of Cohen. It’s to honor the memory of these police officers who stood up for justice and didn’t allow crime to overtake the city.

Ruben, after the shooting in Aurora, Colorado, you decided to go back and change a scene in the film. How do you feel about that decision?

FLEISCHER: The Aurora shooting was an unspeakable tragedy. Out of respect for the families of the victims, we felt it necessary to reshoot that sequence. I’m proud of the fact that we did that, and we didn’t compromise the film or the intent. I think that the Chinatown sequence is a really strong sequence. We should all respect the tragedy and not draw associations to our film, as a result of any of these types of tragedies.